This is a fine article by Joseph Cumming at Enrichment Journal.
By Joseph Cumming
When you talk about matters of faith with your nonbelieving secular neighbors, what Christian belief do they object to most? Is it the biblical concept of hell? Your views on gay marriage? The inerrancy of Scripture? For many of your Muslim neighbors, these Christian beliefs are not offensive. Indeed, your Muslim neighbor may mostly agree with you on these points. But most Muslims do find deeply offensive another belief that is central to the Christian faith — the assertion that Jesus Christ is the “Son of God.”